Seton Placement is the Recommended Treatment
For a patient with a low transsphincteric fistula, prior fistulotomy history, and engagement in receptive anal sex, seton placement is strongly recommended over repeat fistulotomy to prevent catastrophic incontinence that would be functionally devastating for quality of life. 1
Why Seton Over Fistulotomy in This Case
Critical Risk Factors Present
- Prior fistulotomy history dramatically increases the risk of compromised sphincter function, making any additional sphincter division dangerous and potentially catastrophic 1
- Receptive anal intercourse makes any degree of incontinence functionally devastating for quality of life, requiring maximum sphincter preservation 1
- Even "low" transsphincteric fistulas involve sphincter muscle and require a sphincter-preserving approach in high-risk patients like this one 1
Incontinence Risk Data
- Simple fistulotomy without reconstruction carries a 10-20% baseline risk of continence disturbances 1
- Cutting setons result in a 57% incontinence rate from progressive sphincter transection 1, 2, 3
- In patients with prior sphincter surgery, the additional risk of impairment of continence is approximately 20%, with most representing minor incontinence 4
- However, in this patient engaging in receptive anal sex, even minor incontinence would be unacceptable 1
Recommended Treatment Algorithm
Step 1: Loose Non-Cutting Seton Placement
- Place a loose, non-cutting seton through the fistula tract running through the sphincter complex ending in the internal opening to maintain drainage and prevent abscess recurrence 1, 2
- Use soft material such as fine silastic setons for a low-profile, comfortable option 2
- The seton maintains drainage while preserving sphincter integrity 5
Step 2: Seton as Definitive Treatment
- Seton drainage alone can achieve fistula closure in 13.6-100% of cases and can be definitive treatment 1, 2
- Keep the seton in place for variable durations (3 weeks to 40 months depending on clinical response) 2
- Loose setons combined with optimal medical therapy achieved seton removal in up to 98% of patients at a median of 33 weeks 2
Step 3: If Seton Drainage Fails
- Consider the LIFT (ligation of intersphincteric fistula tract) procedure as a second-line sphincter-preserving treatment 1
- LIFT achieved 82% primary healing in low transsphincteric fistulas, with the remaining 18% converting to intersphincteric fistulas that could then undergo fistulotomy with external sphincter preservation 6
- Overall healing rate with LIFT was 100% without affecting fecal continence 6
Common Pitfalls to Avoid
- Do not perform aggressive probing to define the tract, as this causes iatrogenic complications and sphincter injury 1
- Do not perform aggressive dilation, as this causes permanent sphincter injury 1
- Never assume that "low" transsphincteric fistulas are safe for fistulotomy in high-risk patients—any transsphincteric fistula involves sphincter muscle 1
- Avoid rushing to definitive surgery, as seton drainage alone can be curative and allows time for inflammation to subside 1
- Never use cutting setons, which require tightening every 3-4 weeks and carry unacceptable incontinence rates 2, 3
Addressing the Conflicting Recommendations
While the specialist recommending fistulotomy may be correct that fistulotomy can achieve healing rates approaching 100% in carefully selected patients 3, this patient is NOT a carefully selected candidate due to:
- Prior fistulotomy creating compromised baseline sphincter function 1
- Engagement in receptive anal sex making continence preservation paramount 1
- The 10-20% baseline incontinence risk being unacceptable in this context 1
The guideline evidence from the American Society of Colon and Rectal Surgeons explicitly states that sphincter-preserving approaches are strongly recommended for patients with prior fistulotomy history 1, making the seton recommendation the evidence-based choice that prioritizes quality of life outcomes.